Course: Visual Assessment of Children: The Orthoptist Role

Presented on Wednesday 9 February 2005

The Assessment and Treatment of Visual Perceptual Disorders in Dyslexia and Developmental Co-ordination Disorder

presented in February 2005

Nadia Northway PhD BA DBO SRO
N.Northway@gcal.ac.uk

Visual aspects of DCD and Dyslexia

• Dyslexia and DCD are commonly found together therefore some overlap of visual problems
• Low fusional reserves( compensates for ocular drift)
• Low accommodation facility and amplitude ( focussing)
• Poor convergence
• Eye movement difficulties( saccades and SP)
• Head commonly moves instead of eyes
• Visual perceptual problems: visual figure ground, visual sequential memory, visual closure, visual memory, visual spatial relationships, form constancy

Meares-Irlen syndrome/Pattern Sensitivity

Ocular Symptoms and Causes

• Fatigue
• Headaches
• Diplopia
• Blurring of print
• Movement of print
• Restlessness
• Missing words and lines
• Head Movement
• Poor convergence, jump convergence
• Strabismus or poor binocular vision (Squint)
• Poor accommodation amplitude ( focussing)
• Scanning/Tracking problems
• Meares-Irlen syndrome
• Saccadic problems
• Attentional problems

Educational Symptoms and possible Causes

• Poor copying : poor spatial memory and poor sequential memory, poor eye movement especially voluntary saccadic control, interference from inappropriate body movement
• Poor writing:Immature motor skills, poor pencil grip, poor visual discrimination results in left right confusion, irregular size if MIS or other perceptual problems
• Poor spacing of writing -Poor spatial vision and MIS, poor visual perception
• Restlessness : Meares-Irlen syndrome, ocular discomfort, Sensory integration disorder
• Poor Reading : Saccadic problems, ocular problems, MIS, poor visual memory, poor phonic ability
• Poor Spelling : poor visual memory, poor phonics, poor visual sequential memory
• Missing words and lines: poor eye movement, poor attention, poor visuo-spatial skills, poor tracking
• Difficulty with written versus typed writing: If poor form constancy evident child may have difficulty with different presentations of writing e.g. handle , handle

Assessment Carried out at GCU

• Orthoptic assessment
• Overlays
• Eye movement assessment
• Visual discrimination test
• VMI Beery Test ( recently acquired)
• TVPS revised
• Angels in the snow
• Various physical tests such as hopping, finger sequencing
• Sensory Profile questionnaire
• Movement ABC screening questionnaire
• Processing speed and other cognitive assessment if necessary

Intuitive Overlays

• Perspex sheets with gloss and matt surface
• 30 colour combinations possible
• Assess reading speed with and without to determine prognosis
• Time 15 minutes
  

Intuitive Colorimeter

• Alters hue and saturation without changing luminance
• Patient views crowded text.
• Time 15-30 minutes
• Depends on patient!
  

Testing eye movement

• Use of eye tracker
• Saccades: 3 positions
• Anti-saccade using two pens
• Reading speed
• OKN
• Developmental eye movement test

Developmental eye movement test

• Compare horizontal and vertical scanning ability
• Gives age related performance

In recent study 85% of children with DCD gave poor performance

Visuo-spatial difficulties/ Optic ataxia/ Simultaneous Perception

• Leads to problems with copying and reading in classroom, loses place or takes long time to find next word or letter
• Planning next movement difficult since do not have internal map
• Child may not be able to chose where to look- problems with visually guided movement
• Impaired simultaneous perception- if too much information available visually child cannot find relevant info

Orthoptic Therapy

• Prescribe refractive error
• Convergence treatment
• Accommodation exercises using Tromboning, Dinosaur cards, Dot card, Flippers

Saccadic Training

• Dot Card and Dinosaur Card
• Saccadic Trainer
• Physical Games
• Computer aids such as Acereader

Scanning therapy

• Scanning treatment
• Letter searches
• Word searches
• Tracing
• Tachistoscope
• Computer programme such as ace readers
  

Other Therapies

• Brain Gym
• Sensory Integration Therapy
• Multi-sensory learning
• One to One teaching
• Perceptual training , pegboards, flashcards, dominoes, playing cards, visual search tasks
• Occupational therapy

Visuospatial memory strategies

• Position in classroom
• Positioning of copy material
• Games practice
• Search games
• Jigsaws etc
• Happy Families

Recommendations

• Assessment by orthoptist
• Consider spacing of text and font used- enlarge
• Scanning exercises or eye movement exercises
• Overlays
• Orthoptic treatment
• Break up reading tasks
• Computer -change background, font etc
• Change paper colour or sheen
• Position in classroom and books
• Tachistoscope

Conclusions

• Visual problems are part of dyslexia and DCD but many are treatable.
• Improvement in visual function can help teacher facilitate academic improvement.
• Many treatment options may be necessary to improve classroom function.
• Problems of print size etc and issues with visually impairment support.

Visual Assessment of Children: The Orthoptist Role